What is the ruling on blocking a friend who harms the questioner and causes her problems, defends people of innovation, and does not benefit her religiously or worldly? And is that considered an offense to the questioner's religious commitment and morals?

It is forbidden to abandon a Muslim for more than three days, unless there is a legitimate Sharia reason, as the Messenger of Allah, peace and blessings be upon him, said: "It is not lawful for a Muslim to abandon his brother for more than three nights, where they meet and one turns away and the other turns away. The better of them is the one who initiates the greeting of peace" (Narrated by Al-Bukhari).

If advice is unhelpful with someone whose company and conversation you fear, then a graceful avoidance and distance from her is better than associating with her, because she will remember your slips, and you will not be safe from the ill consequences of associating with her. And perhaps a graceful separation is better than harmful association. This is if you fear from associating with her something that would corrupt your religion or cause harm to your religion or worldly life. As for merely blocking her on social media, it is not considered abandonment.